Abstract
In Escherichia coli the dnaQ+ gene, which encodes epsilon, a fidelity subunit of DNA polymerase III, and the rnh+ gene, which encodes RNase H, share a promoter region but are transcribed in opposite directions. The presence of this divergent transcriptional unit on a multicopy plasmid inhibited by as much as 10-fold mutations induced by the SOS-dependent mutagens methyl methanesulfonate and UV light. Mutations in either gene eliminated the effect, suggesting that both genes contribute either directly or indirectly to the antimutagenic phenotype. Neither survival to mutagen exposure nor induction of the SOS response was comparably affected by the presence of the genes. Although the antimutagenic phenotype was partially suppressed by excess UmuDC proteins, which are required for SOS mutagenesis, the presence of the dnaQ+-rnh+ clone also reduced the induction of mutations by N-methyl-N'-nitro-N-nitrosoguanidine in cells deficient for SOS mutagenic processing. The results suggest that the presence of the dnaQ+-rnh+ divergent transcriptional unit interferes with an underlying mutagenic mechanism that is normally facilitated by the proteins induced as part of the SOS response.
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- Baker T. A., Kornberg A. Transcriptional activation of initiation of replication from the E. coli chromosomal origin: an RNA-DNA hybrid near oriC. Cell. 1988 Oct 7;55(1):113–123. doi: 10.1016/0092-8674(88)90014-1. [DOI] [PubMed] [Google Scholar]
- Blanco M., Herrera G., Aleixandre V. Different efficiency of UmuDC and MucAB proteins in UV light induced mutagenesis in Escherichia coli. Mol Gen Genet. 1986 Nov;205(2):234–239. doi: 10.1007/BF00430433. [DOI] [PubMed] [Google Scholar]
- Bridges B. A., Woodgate R. Mutagenic repair in Escherichia coli: products of the recA gene and of the umuD and umuC genes act at different steps in UV-induced mutagenesis. Proc Natl Acad Sci U S A. 1985 Jun;82(12):4193–4197. doi: 10.1073/pnas.82.12.4193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burckhardt S. E., Woodgate R., Scheuermann R. H., Echols H. UmuD mutagenesis protein of Escherichia coli: overproduction, purification, and cleavage by RecA. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1811–1815. doi: 10.1073/pnas.85.6.1811. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Christensen J. R., LeClerc J. E., Tata P. V., Christensen R. B., Lawrence C. W. UmuC function is not essential for the production of all targeted lacI mutations induced by ultraviolet light. J Mol Biol. 1988 Oct 5;203(3):635–641. doi: 10.1016/0022-2836(88)90198-2. [DOI] [PubMed] [Google Scholar]
- Elledge S. J., Walker G. C. Proteins required for ultraviolet light and chemical mutagenesis. Identification of the products of the umuC locus of Escherichia coli. J Mol Biol. 1983 Feb 25;164(2):175–192. doi: 10.1016/0022-2836(83)90074-8. [DOI] [PubMed] [Google Scholar]
- Fersht A. R., Knill-Jones J. W. Contribution of 3' leads to 5' exonuclease activity of DNA polymerase III holoenzyme from Escherichia coli to specificity. J Mol Biol. 1983 Apr 25;165(4):669–682. doi: 10.1016/s0022-2836(83)80273-3. [DOI] [PubMed] [Google Scholar]
- Foster P. L., Dalbadie-McFarland G., Davis E. F., Schultz S. C., Richards J. H. Creation of a test plasmid for detecting G-C-to-T-A transversions by changing serine to arginine in the active site of beta-lactamase. J Bacteriol. 1987 Jun;169(6):2476–2481. doi: 10.1128/jb.169.6.2476-2481.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. L., Davis E. F. Loss of an apurinic/apyrimidinic site endonuclease increases the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine to Escherichia coli. Proc Natl Acad Sci U S A. 1987 May;84(9):2891–2895. doi: 10.1073/pnas.84.9.2891. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. L., Eisenstadt E., Cairns J. Random components in mutagenesis. Nature. 1982 Sep 23;299(5881):365–367. doi: 10.1038/299365a0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. L., Eisenstadt E. Induction of transversion mutations in Escherichia coli by N-methyl-N'-nitro-N-nitrosoguanidine is SOS dependent. J Bacteriol. 1985 Jul;163(1):213–220. doi: 10.1128/jb.163.1.213-220.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. L., Groopman J. D., Eisenstadt E. Induction of base substitution mutations by aflatoxin B1 is mucAB dependent in Escherichia coli. J Bacteriol. 1988 Aug;170(8):3415–3420. doi: 10.1128/jb.170.8.3415-3420.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Foster P. L., Sullivan A. D. Interactions between epsilon, the proofreading subunit of DNA polymerase III, and proteins involved in the SOS response of Escherichia coli. Mol Gen Genet. 1988 Nov;214(3):467–473. doi: 10.1007/BF00330482. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hevroni D., Livneh Z. Bypass and termination at apurinic sites during replication of single-stranded DNA in vitro: a model for apurinic site mutagenesis. Proc Natl Acad Sci U S A. 1988 Jul;85(14):5046–5050. doi: 10.1073/pnas.85.14.5046. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Howard-Flanders P., Boyce R. P., Theriot L. Three loci in Escherichia coli K-12 that control the excision of pyrimidine dimers and certain other mutagen products from DNA. Genetics. 1966 Jun;53(6):1119–1136. doi: 10.1093/genetics/53.6.1119. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jonczyk P., Fijalkowska I., Ciesla Z. Overproduction of the epsilon subunit of DNA polymerase III counteracts the SOS mutagenic response of Escherichia coli. Proc Natl Acad Sci U S A. 1988 Dec;85(23):9124–9127. doi: 10.1073/pnas.85.23.9124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kanaya S., Crouch R. J. DNA sequence of the gene coding for Escherichia coli ribonuclease H. J Biol Chem. 1983 Jan 25;258(2):1276–1281. [PubMed] [Google Scholar]
- Kato T., Shinoura Y. Isolation and characterization of mutants of Escherichia coli deficient in induction of mutations by ultraviolet light. Mol Gen Genet. 1977 Nov 14;156(2):121–131. doi: 10.1007/BF00283484. [DOI] [PubMed] [Google Scholar]
- Kenyon C. J., Brent R., Ptashne M., Walker G. C. Regulation of damage-inducible genes in Escherichia coli. J Mol Biol. 1982 Sep 25;160(3):445–457. doi: 10.1016/0022-2836(82)90307-2. [DOI] [PubMed] [Google Scholar]
- Kenyon C. J., Walker G. C. DNA-damaging agents stimulate gene expression at specific loci in Escherichia coli. Proc Natl Acad Sci U S A. 1980 May;77(5):2819–2823. doi: 10.1073/pnas.77.5.2819. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kogoma T. RNase H-defective mutants of Escherichia coli. J Bacteriol. 1986 May;166(2):361–363. doi: 10.1128/jb.166.2.361-363.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Little J. W. Autodigestion of lexA and phage lambda repressors. Proc Natl Acad Sci U S A. 1984 Mar;81(5):1375–1379. doi: 10.1073/pnas.81.5.1375. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loeb L. A. Apurinic sites as mutagenic intermediates. Cell. 1985 Mar;40(3):483–484. doi: 10.1016/0092-8674(85)90191-6. [DOI] [PubMed] [Google Scholar]
- Loechler E. L., Green C. L., Essigmann J. M. In vivo mutagenesis by O6-methylguanine built into a unique site in a viral genome. Proc Natl Acad Sci U S A. 1984 Oct;81(20):6271–6275. doi: 10.1073/pnas.81.20.6271. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lu C., Scheuermann R. H., Echols H. Capacity of RecA protein to bind preferentially to UV lesions and inhibit the editing subunit (epsilon) of DNA polymerase III: a possible mechanism for SOS-induced targeted mutagenesis. Proc Natl Acad Sci U S A. 1986 Feb;83(3):619–623. doi: 10.1073/pnas.83.3.619. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maki H., Horiuchi T., Sekiguchi M. Structure and expression of the dnaQ mutator and the RNase H genes of Escherichia coli: overlap of the promoter regions. Proc Natl Acad Sci U S A. 1983 Dec;80(23):7137–7141. doi: 10.1073/pnas.80.23.7137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maki H., Kornberg A. Proofreading by DNA polymerase III of Escherichia coli depends on cooperative interaction of the polymerase and exonuclease subunits. Proc Natl Acad Sci U S A. 1987 Jul;84(13):4389–4392. doi: 10.1073/pnas.84.13.4389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marsh L., Walker G. C. Cold sensitivity induced by overproduction of UmuDC in Escherichia coli. J Bacteriol. 1985 Apr;162(1):155–161. doi: 10.1128/jb.162.1.155-161.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller J. H. Carcinogens induce targeted mutations in Escherichia coli. Cell. 1982 Nov;31(1):5–7. doi: 10.1016/0092-8674(82)90398-1. [DOI] [PubMed] [Google Scholar]
- Mount D. W. A mutant of Escherichia coli showing constitutive expression of the lysogenic induction and error-prone DNA repair pathways. Proc Natl Acad Sci U S A. 1977 Jan;74(1):300–304. doi: 10.1073/pnas.74.1.300. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nohmi T., Battista J. R., Dodson L. A., Walker G. C. RecA-mediated cleavage activates UmuD for mutagenesis: mechanistic relationship between transcriptional derepression and posttranslational activation. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1816–1820. doi: 10.1073/pnas.85.6.1816. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nomura T., Aiba H., Ishihama A. Transcriptional organization of the convergent overlapping dnaQ-rnh genes of Escherichia coli. J Biol Chem. 1985 Jun 10;260(11):7122–7125. [PubMed] [Google Scholar]
- Quiñones A., Kücherer C., Piechocki R., Messer W. Reduced transcription of the rnh gene in Escherichia coli mutants expressing the SOS regulon constitutively. Mol Gen Genet. 1987 Jan;206(1):95–100. doi: 10.1007/BF00326542. [DOI] [PubMed] [Google Scholar]
- Roberts J. W., Roberts C. W. Two mutations that alter the regulatory activity of E. coli recA protein. Nature. 1981 Apr 2;290(5805):422–424. doi: 10.1038/290422a0. [DOI] [PubMed] [Google Scholar]
- Scheuermann R., Tam S., Burgers P. M., Lu C., Echols H. Identification of the epsilon-subunit of Escherichia coli DNA polymerase III holoenzyme as the dnaQ gene product: a fidelity subunit for DNA replication. Proc Natl Acad Sci U S A. 1983 Dec;80(23):7085–7089. doi: 10.1073/pnas.80.23.7085. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shinagawa H., Iwasaki H., Kato T., Nakata A. RecA protein-dependent cleavage of UmuD protein and SOS mutagenesis. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1806–1810. doi: 10.1073/pnas.85.6.1806. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shinagawa H., Kato T., Ise T., Makino K., Nakata A. Cloning and characterization of the umu operon responsible for inducible mutagenesis in Escherichia coli. Gene. 1983 Aug;23(2):167–174. doi: 10.1016/0378-1119(83)90048-3. [DOI] [PubMed] [Google Scholar]
- Singer B., Sági J., Kuśmierek J. T. Escherichia coli polymerase I can use O2-methyldeoxythymidine or O4-methyldeoxythymidine in place of deoxythymidine in primed poly(dA-dT).poly(dA-dT) synthesis. Proc Natl Acad Sci U S A. 1983 Aug;80(16):4884–4888. doi: 10.1073/pnas.80.16.4884. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sninsky J. J., Uhlin B. E., Gustafsson P., Cohen S. N. Construction and characterization of a novel two-plasmid system for accomplishing temperature-regulated, amplified expression of cloned adventitious genes in Escherichia coli. Gene. 1981 Dec;16(1-3):275–286. doi: 10.1016/0378-1119(81)90083-4. [DOI] [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- VOGEL H. J., BONNER D. M. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed] [Google Scholar]
- Walker G. C. Mutagenesis and inducible responses to deoxyribonucleic acid damage in Escherichia coli. Microbiol Rev. 1984 Mar;48(1):60–93. doi: 10.1128/mr.48.1.60-93.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Witkin E. M., Roegner-Maniscalco V., Sweasy J. B., McCall J. O. Recovery from ultraviolet light-induced inhibition of DNA synthesis requires umuDC gene products in recA718 mutant strains but not in recA+ strains of Escherichia coli. Proc Natl Acad Sci U S A. 1987 Oct;84(19):6805–6809. doi: 10.1073/pnas.84.19.6805. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woodgate R., Bridges B. A., Herrera G., Blanco M. Mutagenic DNA repair in Escherichia coli. XIII. Proofreading exonuclease of DNA polymerase III holoenzyme is not operational during UV mutagenesis. Mutat Res. 1987 Jan;183(1):31–37. doi: 10.1016/0167-8817(87)90042-3. [DOI] [PubMed] [Google Scholar]